Acquisition of a temporary right via transmission of a near-field radio wave

ABSTRACT

The disclosed technology relates to a method for receiving a near-field radio wave, the wave being received using electromagnetic-wave conduction capacities of the body of a user who is able to make a validation gesture that modifies characteristics of the radio wave. The method includes detecting a first modification of a characteristic of the radio wave, the first modification being resultant from a start of the gesture, and detecting a second modification of a characteristic of the radio wave, the second modification being resultant from an end of the gesture, where the acquisition of a right for the user is dependent on the first modification and the second modification.

INCORPORATION BY REFERENCE TO ANY PRIORITY APPLICATIONS

Any and all applications for which a foreign or domestic priority claimis identified in the Application Data Sheet as filed with the presentapplication are hereby incorporated by reference under 37 CFR 1.57.

This application claims priority to French Patent Application No.2003241, filed Apr. 1, 2020, the disclosure of which is herebyincorporated by reference in its entirety.

BACKGROUND Technical Field

The disclosed technology relates to short-range wireless communicationsfor transmitting data between two devices, and in particular totransmission of data between two devices by way of the human body.

Description of the Related Art

Near-field communications, which can be referred to using the acronymNFC (“Near Field Communication”), and which can be mainly based on thestandard ISO 14443 (International Standard Organization), use wirelesstechnologies in order to allow data to be exchanged between twoperipherals that are separated by a short distance, typically onesmaller than ten centimeters. Communications of this type have manyapplications, for example in the fields of payment or transportation.The near-field receiver receives a message from the near-field sender.Such a message may correspond, in the aforementioned context, to thevalidation of a transaction, such as for example the exchange of aticket (for an event, for travel, etc.); a payment; the launch of apersonalized service on a computer or a television set; access to aroom; etc.

In some embodiments, a system allowing such messages to be exchanged canbe a system in which system the receiver is contained in a terminalborne by a user, the messages being received by the receiver during anintra-body communication via the user of the terminal. An intra-bodycommunication uses the conductivity capacity of the human body totransmit the electromagnetic waves that carry the wirelesscommunications. Such a technology is called intra-body communication(IBC).

Such a wireless communication system comprises a terminal borne by auser, the antenna of which either makes direct contact with the user, oris very close thereto, being for example located in an item of clothingor a bag. It furthermore comprises an NFC touchpoint comprising anemitter the antenna of which is for example integrated into a sensingarea to which the user may make an approaching gesture, for exampleplacing his hand on the antenna, swiping it or merely bringing his handa few centimeters closer to the antenna. A signal sent by the touchpointis modulated by means of a low-frequency modulator and transmittedthrough the body of the user. Specifically, the human body hasconduction capacities that are suitable for conveying suchelectromagnetic signals provided that the emitting antenna is located inproximity (less than a few centimeters) from the body of the user.

The terminal receives the signal because of the physical contact, or atthe very least the close proximity, of the user to the antenna of thetouchpoint. The received signal is demodulated and optionallytransmitted to an equipment suitable for performing processingoperations, and in the present case for carrying out a transaction(payment, opening a door, etc.). In other embodiments, the terminalborne by the user operates in send mode and the NFC touchpoint inreceive mode, or indeed both work in two-way mode.

In order to secure this type of transaction, it is suggested in documentWO2016/001506 to detect and validate an approaching gesture of the user,in order to ensure that the gesture is intentional and not accidental.The combination of NFC and IBC technologies in this such implementationstherefore allows the accordance of a right to be triggered by making itdependent on the detection of this validation gesture, but is notsuitable for every type of right, for example when the attribution ofthe right must be dependent on time-domain characteristics of thegesture, or on a set of gestures executed by a plurality of users.

One of the aims of the disclosed technology is to remedy these drawbacksof other such implementations.

SUMMARY

The disclosed technology aims to improve the situation by virtue of, inone broad aspect, a method for receiving a near-field radio wave (NFC),the wave being received using electromagnetic-wave conduction capacitiesof the body (IBC) of a user who is able to make a validation gesturethat modifies characteristics of the radio wave, the method comprising:

-   -   detecting a first modification of a characteristic of the radio        wave, the first modification being resultant from a start of        said gesture,    -   detecting a second modification of a characteristic of the radio        wave, the second modification being resultant from an end of        said gesture,

the acquisition of a right for the user being dependent on the firstmodification and the second modification.

The validation gesture is for example the hand of the user momentarilybeing placed on the reader of an NFC touchpoint. One object of themethod resides in the separation of the detection of the hand beingplaced on an NFC touchpoint, from the detection of the removal of thehand.

The detection of the start of the gesture may consist in a detection ofan increase in the energy of the NFC signal or of its derivative above acertain threshold. Likewise, the detection of the end of the gesture mayconsist in a detection of a decrease in the energy of the NFC signal orof its derivative above a certain threshold.

In other implementations, it is the validation gesture in its entiretythat is detected, this for example allowing a right to be granted to thebenefit of the user. To rescind this right, in such otherimplementations, it is necessary to make recourse to an externalcriterion such as a predefined lifetime of the right, or to theoccurrence of a particular event independent of the validation gesturemade by the user. The term “right” here means any right, privilege orauthorization that is inaccessible to the user except if he makes theexpected validation gesture.

By virtue of the proposed method, it is possible to link the lifetime ofthe right directly to the duration of the validation gesture. The rightis acquired if the expected validation gesture made by the user lastsfor a length of time comprised between two precise moments in time.

For example, this allows the access of the user to a service or to aroom to be limited solely to the period of contact between his hand andan NFC touchpoint. For example, the period of contact thus determinedmay correspond to the period for which an electrical lock of a door isunlocked.

In another application, it is also possible to make the acquisition of aparticular right intended to be consumed subsequently dependent on theexecution of the validation gesture at a predefined moment: it isnecessary for the start and end of the gesture to be detected, and toverify that they indeed flank the predefined moment.

According to one aspect of the receiving method, the radio wavecomprises frames, the method comprising extracting an identifier of adevice that sent the near-field radio wave, from a frame.

By virtue of this aspect, the right manager is able to identify theright to be attributed depending on the device used to send the radiowave, which is an NFC touchpoint for example.

According to one aspect of the receiving method, the radio wavecomprises frames, the method comprising extracting, from at least oneframe, a time-variable verification code, which code is referred to as arandom factor.

By virtue of this aspect, the right manager is able to verify at whatmoment the gesture was made by the user. The random factor is forexample a code generated using a random function that is usedsynchronously both by the rights manager and by the sender of the radiowave. A new code may be generated periodically. If the code is inaddition unique to the sender of the near-field radio wave and allowsthe manager to identify it, it is no longer necessary for the identifierof the sending device to be transmitted in the detection message. Thecode, which is not falsifiable, in addition to allowing a timestamp tobe deduced, also allows the rights manager to verify that the identifieroptionally present in the detection message is indeed that of the devicethat sent the radio wave.

The term timestamp is here to be understood to mean a value representinga moment in time. This value may be absolute, such as a universal timevalue, or be relative to a start point; for example, the timestamp ofdetection of the start of a validation gesture may have the value zeroand the timestamp of detection of the end of the gesture may have avalue representing the length of time passed since the start timestamp.

According to one aspect of the receiving method, it comprises sending amessage relating to at least one detection, called the detectionmessage, to a server that manages said right.

By virtue of this aspect, the conditions of acquisition of the right maybe verified when the right manager is not comprised in the deviceimplementing the proposed method, i.e. when the right that the userdesires to acquire is not managed locally.

According to one aspect of the receiving method, the detection messagecomprises at least one element of a group comprising:

-   -   an identifier of the device that sent the near-field radio wave,    -   a random factor,    -   a datum relating to the user.

By virtue of the identifier of the sending device, the remote rightmanager may identify which right is being requested by the user.

By virtue of the random factor, the remote right manager may verify theidentifier of the sending device and/or the timestamp of the validationgesture.

By virtue of the datum relating to the user, the remote right managermay verify whether the user is indeed entitled to receive the right thathe is requesting. The datum relating to the user may simply be anidentifier of the mobile terminal used by the user.

According to one aspect of the receiving method, a plurality ofsuccessive detection messages are sent up to the detection of the secondmodification, the first message of the series being sent as soon as thefirst modification is detected.

By virtue of this aspect, the rights manager may maintain the right foras long as valid detection messages, i.e. messages containing the dataexpected by the manager, are sent thereto. The lifetime of the acquiredright is therefore a multiple of the length of time passing between eachmessage send time.

According to one aspect of the receiving method, before a datum isextracted from a frame a message indicative of the detection of thevalidation gesture, called the return message, is sent to the devicethat sent the near-field radio wave.

By virtue of this aspect, the terminal may indicate to the touchpointthat sent the radio wave that it is ready to communicate. This increasessecurity because it allows the touchpoint to wait for this moment beforesending a frame comprising its identifier and/or its code (randomfactor) in frames of the radio wave. Thus, the identifier of thetouchpoint and/or its code cannot be accidentally or maliciouslycaptured by a terminal of another user without an intentional validationgesture on the part of the user.

In another broad aspect, the disclosed technology also relates to adevice for receiving a near-field radio wave, the wave being receivedusing electromagnetic-wave conduction capacities of the body of a userwho is able to make a validation gesture that modifies characteristicsof the radio wave, the device comprising a detection circuit, aprocessor and a memory that is coupled to the processor and thatcontains instructions that are intended to be executed by the processorin order to:

-   -   detect a first modification of a characteristic of the radio        wave, the first modification being resultant from a start of        said gesture,    -   detect a second modification of a characteristic of the radio        wave, the second modification being resultant from an end of        said gesture,

the acquisition of a right for the user being dependent on thedetections.

This device, which in all its embodiments is able to implement thereceiving method that has just been described, is intended to beimplemented in a user terminal, for example a mobile terminal borne byits user, for example held in his hand or located in an item of clothingor in a bag. The two moments, of detection of the first modificationindicative of the start of the validation gesture, and of detection ofthe second modification indicative of its end, respectively, limit intime the attributed right.

In another broad aspect, the disclosed technology also relates to asystem for acquiring a temporary right, comprising:

-   -   a receiving device such as that described above,    -   a sending device, able to emit a near-field radio wave, and    -   a rights-managing device, able to attribute a right depending on        at least one datum relating to the start and to the end of the        validation gesture.

In such a system, the receiving device is for example comprised in amobile terminal borne by its user, the sending device is for examplecomprised in an NFC touchpoint, and the managing device is for examplecomprised in a rights server. The rights manager may or may not beseparate from the mobile terminal. When it is separate therefrom, it isimportant that it communicates therewith without excessive latency via acommunication technology other than NFC, via a 3GPP cellularcommunication network for example.

A so-called NFC touchpoint comprises an NFC antenna for sending, and incertain cases receiving, a near-field wave, which may be composed of NFCframes. This antenna may be placed behind a solid screen, or integratedinto this screen, the latter also being referred to as a touch surface.This surface may be touched or swiped by the user, with his hand forexample. The NFC wave sent by the touchpoint with start characteristicspasses through the body of the user and is received by the mobileterminal with end characteristics. The differences between the start andend characteristics of the wave depend on the location of the body ofthe user with respect to the touchpoint and with respect to theterminal, and on characteristics related to the propagation medium ofthe wave. The latter characteristics are intrinsic to the user, i.e.characteristics such as his physiological characteristics, the clothesthat he is wearing, etc.

In one embodiment, the rights server must be able to determine at leasttwo things: the right requested by the user, and the period for whichthe requested right must be accorded.

To identify the requested right, an identifier of the NFC touchpoint maysuffice. This identifier may be comprised in the NFC frames sent by thetouchpoint, and received by the terminal. The terminal may extract thisidentifier and send it to the rights server in the message referred toas the detection message. Regarding the period for which the right mustbe accorded, the terminal may furthermore insert, into the detectionmessage, a timestamp of the start and a timestamp of the end of thevalidation gesture made by the user, and detected by the terminal.

According to one aspect of the system for acquiring a temporary right,

-   -   the sending device comprises a means for detecting a physical        contact with the user, and    -   the rights-managing device is furthermore able to attribute the        right depending on a datum relating to physical contact.

In another embodiment, the rights server may want to verify that theassociation between the terminal and the NFC touchpoint is real, and notthe result of happenstance or intentionally simulated. This may forexample be the case if the terminal passes by accident in proximity tothe touchpoint, or if a non-legitimate user has the identifier of thetouchpoint in his possession and makes it so that it is inserted into adetection message intended for the rights server, without the terminalbeing in proximity to the touchpoint. This is prevented if thetouchpoint detects a contact between the user and itself, through thetouch surface for example, and sends to the rights server a datumrelating to this contact.

According to one aspect of the system for acquiring a temporary right,

-   -   the sending device furthermore comprises a means for inserting,        into the near-field radio wave, a random factor known to the        rights-managing device, and    -   the receiving device furthermore comprises a means for        extracting said random factor, and a means for transmitting said        random factor to the rights-managing device.

In another embodiment, the rights server may want to verify that thetimestamp of the start and the timestamp of the end of the validationgesture are valid and have not been invented or falsified by theterminal. To this end, a value known both to the NFC touchpoint and tothe rights server is generated in a sequence, with a periodicity andwith a precise synchronization. This value is referred to as the randomfactor. Knowing a random factor, the rights server is therefore capableof determining the exact moment at which the random factor wasgenerated—the reliability of a timestamp is a direct result of thereliability of the random factor. It is also understood that thefrequency of renewal of the random factors, or, more exactly, the timeinterval separating two generations of random factor, determines themargin of precision of the timestamps.

If in the detection message the terminal communicates both an extractedrandom factor and a declared timestamp, the rights server may comparethe timestamp declared by the terminal with that corresponding to therandom factor, and prevent the attribution of the requested right in theabsence of correspondence.

The NFC touchpoint and the rights server must possess the same randomfactor at the same time. This may be achieved in various ways: eitherthe random factor is generated separately by each thereof, using anidentically programmed random-factor generator, or only one thereofgenerates it and communicates it to the other in real time via anychannel different from that formed by the near-field radio wave receivedby the terminal of the user.

According to one aspect of the system for acquiring a temporary right,the sending device comprises:

-   -   a means for detecting a physical contact with the user, and    -   a means for inserting, into the near-field radio wave, a random        factor known to the rights-managing device, this means being        activated after detection of the physical contact with the user.

Thus, the random factors cannot be accidentally or maliciously capturedby a terminal of another user without an intentional validation gestureon the part of the user.

In another broad aspect, the disclosed technology also relates to acomputer program comprising instructions that, when these instructionsare executed by a processor, result in it implementing the steps of themethod for receiving a near-field radio wave, as described above.

In another broad aspect, the disclosed technology also relates to a datamedium readable by a device for receiving a near-field radio wave, andcomprising instructions of a computer program such as mentioned above.

The disclosure technology furthermore improves the situation by virtueof, in another broad aspect, a device for managing a right that isattributed on the basis of a plurality of validation gestures made by atleast one user, the gestures modifying a characteristic of a radio waveusing near-field electromagnetic-wave conduction capacities of the bodyof the at least one user, the device comprising a processor and a memorycoupled to the processor and containing instructions intended to beexecuted by the processor in order to:

-   -   obtain a plurality of data relating to detection times of        modifications of a characteristic of a near-field radio wave,        said data being referred to as detection data,    -   attribute the right to the at least one user on the basis of the        times of the detections.

In another broad aspect, the disclosed technology also relates to asystem for attributing a right, comprising:

-   -   sending devices, each being able to emit a near-field radio        wave,    -   devices for receiving near-field radio waves, each being able to        receive a near-field radio wave using electromagnetic-wave        conduction capacities of the body of at least one user able to        make at least one validation gesture that modifies        characteristics of the near-field radio wave, each receiving        device comprising a circuit for detecting a modification of a        characteristic of the radio wave, and    -   a right-managing device such as that described above, the        detection data being delivered by the receiving devices.

By virtue of a right-attributing system according to the disclosedtechnology, it is possible to make the attribution of the rightdependent on the degree of simultaneity or sequence of a plurality ofvalidation gestures made by one or more users to one or more NFCtouchpoints.

According to one aspect of the system for attributing a right, thevalidation gestures of at least two users are taken into account.

The condition of attribution of the right may be the simultaneity of twogestures, made to two NFC touchpoints by two users each bearing onemobile terminal on his person. Each NFC touchpoint comprises a sendingdevice, and each terminal comprises a receiving device that sends to aright-managing device the data relating to the timestamps of thedetections of the gestures. The right, for example initiation of anon-line session allowing access to sensitive data requiring the combinedauthentication of two people (an employee and his hierarchical superiorfor example), will be attributed if the two people both make avalidation gesture to one NFC touchpoint, the NFC touchpoints possiblybeing in different locations, and even very far from each other. Thecombination of the two gestures, i.e. the way in which they are madetimewise, must respect an expected combination, which for example is asimultaneity, or a sequence.

The system also allows two or more users, each with their terminalcomprising a receiving device, to make their gesture to the same NFCtouchpoint comprising a single sending device.

The system also applies to more complicated cases, with any number ofusers and any number of NFC touchpoints, and the condition ofattribution may be more complex than a simple simultaneity or a simplesequence. For example, the gestures may need to be sequenced in acertain order, such an NFC touchpoint being required to follow suchanother.

According to one aspect of the system for attributing a right, twovalidation gestures of a user are taken into account.

The system is also applicable to a very particular case, with a singleuser, and without a mobile terminal. The user must make a gesture witheach of his two hands to two NFC touchpoints that are separate but nottoo far apart from each other, each touchpoint comprising both a sendingdevice and a receiving device. In this case, it is the crossed detectionof the two validation gestures that triggers the attribution of theright. As in the other cases described above, the rights-managing devicemay be comprised in one of the two NFC touchpoints or be separatetherefrom, depending on the type of right in question.

According to one aspect of the system for attributing a right, thedetection circuit of a receiving device is arranged to:

-   -   detect a first modification of a characteristic of the radio        wave, the first modification being resultant from a start of        said gesture,    -   detect a second modification of a characteristic of the radio        wave, the second modification being resultant from an end of        said gesture,

wherein the right-managing device is furthermore able to attribute theright on the basis of the start and end times of the validationgestures.

In order to determine the degree of timewise distribution of thevalidation gestures, it is preferable for the rights-managing device toknow the start and end times of each of the gestures. In the rightsmanager, a timestamp of a validation gesture may either be obtaineddirectly from the detection datum, or deduced indirectly from the timeof reception of the detection datum indicating the start or end of avalidation gesture, or made possible via an indirect datum, such as, forexample, a random factor randomly generated and communicated by thereceiving device in the detection data, the mode of generation of therandom factor, or the random factor in itself, also being known by therights-managing device and allowing it to work out the timestamp of thegestures.

In another broad aspect, the disclosed technology also relates to amethod for managing a right that is attributed on the basis of aplurality of validation gestures made by at least one user, the gesturesmodifying a characteristic of a radio wave using near-fieldelectromagnetic-wave conduction capacities of the body of the at leastone user, the method comprising:

-   -   obtaining a plurality of data relating to detection times of        modifications of a characteristic of a near-field radio wave,        said data being referred to as detection data,    -   attributing the right to the at least one user on the basis of        the times of the detections.

This method may be implemented by the rights-managing device describedabove. The detection data are for example sent by (NFC) devices forreceiving near-field radio waves, such as described above.

If the condition of attribution of the right is a form of simultaneityof all the gestures, it is enough for the method to verify that none ofthe gestures is distant from a defined time by more than a certainthreshold.

If the condition of attribution of the right is a form of sequence ofall the gestures, it is enough for the method to verify that all thegestures follow one another, while optionally respecting a minimum ormaximum time difference between two gestures, and optionally in apredefined order, if it is possible to distinguish between the gesturesor the NFC touchpoints to which the gestures are made.

According to one aspect of the method for managing a right, thedetection data comprise data relating to start and end times of thevalidation gestures, these times defining intervals specific to each ofthe gestures, and the right is attributed depending on a criterionrelating to a timewise distribution of the intervals.

By virtue of the interval data of each of the validation gestures, themethod may verify any type of timewise distribution whatever itscomplexity, simultaneity, sequence, or combination of simultaneity andsequence.

If the criterion is purely a simultaneity of the validation gestures, itis enough to verify that all the intervals have one time in common.

For more complex criteria, it is possible to measure and verify minimumdelays between successive validation gestures, or in contrast periods ofminimum overlap.

According to one aspect of the method for managing a right, thedetection data comprise a time-variable verification code, which isreferred to as the random factor, the random factor having been insertedinto the near-field radio wave by a device that sent the wave.

By virtue of this aspect, it is possible to verify that the timestamp ofthe start and the timestamp of the end of a validation gesture are validand have not been invented or falsified. To this end, a value known bothto the NFC device that sent the radio wave and to the rights-managingdevice is generated in a sequence, with a periodicity and with a precisesynchronization. This value is referred to as the random factor. Knowinga random factor, it is therefore possible to determine the exact momentat which the random factor was generated—the reliability of a timestampis a direct result of the reliability of the random factor. It is alsounderstood that the frequency of renewal of the random factors, or, moreexactly, the time interval separating two generations of random factor,determines the margin of precision of the timestamps.

These random factors may suffice by way of data relating to timestampeddetections of the validation gestures. If these data furthermorecomprise timestamps that are explicitly declared by the wave-receivingdevices, it is possible to compare the declared timestamp with thatcorresponding to the random factor, and to prevent the attribution ofthe requested right in the absence of correspondence.

The device that sent the radio wave and the rights-managing device mustpossess the same random factor at the same time. This may be achieved invarious ways: either the random factor is generated separately by eachthereof, using an identically programmed random-factor generator, oronly one thereof generates it and communicates it to the other in realtime via any channel different from that formed by the near-field radiowave.

According to one aspect of the method for managing a right, each randomfactor is specific to one NFC sending device.

Thus, it is possible for the managing device to distinguish between NFCsending devices solely on the basis of the detection data. It istherefore for example possible to verify that validation gestures haveindeed been made to all the expected sending devices.

In another broad aspect, the disclosed technology also relates to acomputer program comprising instructions that, when these instructionsare executed by a processor, result in it implementing the steps of themanaging method, as described above.

In another broad aspect, the disclosed technology also targets a datamedium readable by a right-managing device, and comprising instructionsof a computer program such as mentioned above.

The abovementioned programs may use any programming language, and be inthe form of source code, object code, or of intermediate code betweensource code and object code, such as in a partially compiled form, or inany other desirable form.

The abovementioned data media may be any entity or device capable ofstoring the program. For example, a medium may include a storage means,such as a ROM, for example a CD-ROM or a microelectronic circuit ROM, orelse a magnetic recording means.

Such a storage means may be for example a hard disk, a flash memory,etc.

Moreover, a data medium may be a transmissible medium such as anelectrical or optical signal, which may be routed via an electrical oroptical cable, by radio or by other means. A program according to thedisclosed technology may in particular be downloaded from an Internetnetwork.

Alternatively, a data medium may be an integrated circuit in which aprogram is incorporated, the circuit being designed to execute or to beused in the execution of the methods in question.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other features of the present disclosure will becomemore fully apparent from the following description and appended claims,taken in conjunction with the accompanying drawings. The followingdescription of certain embodiments of the disclosed technology, whichembodiment is given by way of simple illustrative and non-limitingexample. The appended drawings are given by way of non-limitingexamples. Understanding that these drawings depict only severalembodiments in accordance with the disclosure and are not to beconsidered limiting of its scope, the disclosure will be described withadditional specificity and detail through use of the accompanyingdrawings. In the following detailed description, reference is made tothe accompanying drawings, which form a part hereof. In the drawings,similar symbols typically identify similar components, unless contextdictates otherwise.

FIG. 1 shows an implementation of the method for receiving a radio wave,according to one embodiment.

FIG. 2 shows an example of the power of a near-field radio wavecorresponding to a validation gesture, according to one embodiment.

FIG. 3 shows a system for attributing a right depending on theperformance of validation gestures by a plurality of users.

FIG. 4 shows a system for attributing a right depending on theperformance of a plurality of validation gestures by a single use.

FIG. 5 shows an example of a structure of a device for receiving anear-field radio wave, according to one aspect of the disclosedtechnology.

FIG. 6 shows an example of a structure of a device for managing a rightthat is attributed on the basis of a plurality of validation gesturesmade by at least one user, according to one aspect of the disclosedtechnology.

DETAILED DESCRIPTION

FIG. 1 shows an example of an implementation of the method for receivinga radio wave, according to one embodiment of the disclosed technology.

The user U bears on his person a terminal T, for example a smartphoneable to receive frames of an NFC radio wave. When the user U causes apart of his body, for example one of his hands, to approach a touchpointB that is an emitter of NFC frames, the transmission of these framesstarts to be possible between the touchpoint B and the terminal T,through the body of the user U.

In a step B1, the touchpoint B starts to emit NFC frames. This step maybe triggered depending on a plurality of criteria, which will bediscussed below.

In a step U1, the user U executes, with the touchpoint B, the start of agesture referred to as the validation gesture. This validation gestureis required of him if he is to obtain, in exchange, a particular right.

In an optional step B2, the touchpoint B detects a contact with the userU, for example through a sensing area provided to this end on thetouchpoint B. This detection is an example of an event that may triggerthe emission of NFC frames by the touchpoint B. In this case, step B2occurs before step B1.

It is not necessary for the touchpoint B to detect the contact. Theemission of the NFC frames may indeed also be triggered by anothermeans, for example starting from a certain time, or following an actionof the user that is independent of the validation gesture, such as forexample actuation of a switch on the touchpoint.

When the user starts his validation gesture, the terminal T may start toreceive a radio wave carrying NFC frames, the wave being transmittedthrough the body (IBC) of the user U. From a certain point, in a step T1that is described in more detail with reference to FIG. 2, the power ofthis radio wave becomes sufficient for the terminal T to detect thestart of the validation gesture.

In a step T3(i), the terminal T sends, to a rights manager, which may becomprised in a server S, a detection message msg1. This message may forexample be transmitted through a cellular communication network, or alocal Wi-Fi or Bluetooth network, by way of an SMS message, or using anInternet connection if the network is of 3rd (3G) or subsequentgeneration.

The message msg1 comprises at least one datum indicating to the server Sthat the terminal T has detected the start of a validation gesture madeby the user U.

In addition, the message msg1 may comprise other data that the terminalT must extract from at least one of the received NFC frames, in a stepT2(i) prior to step T3(i).

In this step T2(i), which includes a demodulation of the received radiowave carrying NFC frames, the terminal T therefore receives an NFC framesent by the touchpoint B in a step B3(i).

In step B3(i) the touchpoint B sends an NFC frame into which thetouchpoint B has inserted various data. Among these data the followingmay be found:

-   -   a verification code A(i), which is referred to as the random        factor, intended for the rights manager,    -   an identifier of the touchpoint B, if the code is absent, or        insufficient to allow the touchpoint B to be identified.

The random factor A(i) is a code known both by the touchpoint B and bythe rights manager. It is used to indicate that the NFC frame thatcontains it was indeed sent by the touchpoint B and not by anotherdevice, or to indicate that said frame was sent at a time when this codewas valid (if the code varies over time), or to indicate both of thesethings. Common knowledge of the code by the touchpoint and the rightsmanager may be achieved in a number of ways. Either the random factor isgenerated by one of the two thereof, then communicated in real time tothe other by any means such as an Internet connection which may or maynot be achieved via a cellular network, or both each possess a softwaremodule that generates the same random factors in synchronization.

Still in step T2(i), the terminal T extracts the random factor A(i) fromthe received NFC frame. In one variant, the terminal also extracts, fromthe NFC frame, an identifier of the touchpoint B. It may be recalledthat the random factor A(i) means nothing to the terminal B but allowsit to prove that it has indeed obtained an NFC frame from a certaintouchpoint at a certain time.

In step T3(i), the terminal T therefore sends, to the rights-managingserver S, the detection message msg1, into which the terminal T hasinserted the random factor A(i), in addition to the datum indicating tothe server S that the terminal T has detected the start of a validationgesture.

In a step S1(i), the server S receives the detection message msg1. Byanalyzing this message, using the random factor A(i), the server Sdetermines that a user has made to the touchpoint B the start of avalidation gesture. It is at this time To that the right is “granted”,i.e. that the right passes from a non-activated state to an activatedstate.

In a variant in which the right is personalized, the terminal T alsoinserts an identifier of the user U into the message msg1, this allowingthe server S to determine that it is the user U, and not another user,who is requesting that the right be granted. The identifier of the userU may optionally be accompanied by a password in the message msg1, inthe case where the server S must authenticate the user U, by consultinga separate authentication server, for example.

The user U may also be identified using his physio-dynamic fingerprint,i.e. his way of making the validation gesture. Specifically, thewaveform of the signal received by the terminal T depends on hisphysiological characteristics (morphology, body mass index) and on theway in which he makes his gesture (rapidity of approach and withdrawal,stability). A trail of the gesture may be generated by the terminal andinserted into the detection message. The trail of the gesture may becompared, by the server S, with other trails of a trail databasecontaining at least one trail originating from the legitimate user ofthe terminal T. Alternatively, if the terminal T is considered reliableby the system, recognition of the trail may be entrusted thereto, whichthen consists, for example, in comparing the trail generated by thegesture with a trail stored in memory beforehand locally by thelegitimate user of the terminal. The comparison score may be insertedinto msg1, or else a binary value indicating whether the score is aboveis of a certain threshold or not. The trail of the gesture may even begenerated by the touchpoint B, via use of a passive or active radio- orlight-based technology (including NFC) inter alia (ultrasound, trackpad,fingerprint, etc.), and be inserted into the NFC frame and thenretransmitted via the terminal T, or into a message between thetouchpoint B and the server S, in order that the latter may compare itto a known trail.

In a step U2, the user U executes, with the touchpoint B, the end of thevalidation gesture. When the user ends his validation gesture, from acertain point, in a step T5, which is described in more detail withreference to FIG. 2, the power of this radio wave becomes insufficientand the terminal T detects the end of the validation gesture.

The last NFC frame that the terminal T receives before or at the momentof the detection of the end of the validation gesture is sent, by thetouchpoint B, in a step B4, and is received by the terminal T in a stepT4.

In a step T6, the terminal T sends, to the server S, a detection messagemsg2. The message msg2 comprises at least one datum indicating to theserver S that the terminal T has detected the end of the validationgesture made by the user U.

In addition to the datum indicating the end of the validation gesture,the terminal T inserts, into the message msg2, the random factor A(j)extracted from the NFC frame received in step T4.

In a step S2, the server S receives the detection message msg2. Byanalyzing this message, using the random factor A(j), the server Sdetermines that a user has made to the touchpoint B the end of thevalidation gesture. It is at this time Tf that the right is “rescinded”,i.e. that the right passes from an activated state to a non-activatedstate.

In one embodiment, the random factor is time-variable. The random factormay therefore be used by the right manager (the server S) to associate atimestamp with each of the messages msg1 and msg2 that it receives. Thedegree of precision of this timestamp depends on the frequency at whichthe random factor is generated. If for example one new random factor isgenerated every second, the exactness of the timestamp is at least onesecond.

In this embodiment, a series of N messages msg1 is sent. Steps B3(i),T2(i), T3(i) and S1(i) are repeated N times, with i=1 to N.

The time To at which the right is granted is determined in step S1(1),and the right remains valid provided that the server S keeps verifyingtwo conditions:

-   -   the message msg1 in a step S1(i) is not a detection message msg2        indicating that the end of the validation gesture has been        detected, and    -   the random factor A(i) received in a step S1(i) is correct.

To determine the time Tf at which the right is rescinded, the procedurefollowed is therefore either as above, i.e. the right is rescinded instep S2 on reception of a message msg2 by the server S, or the right isrescinded as soon as the server S detects an incorrect random factorA(i) in the series of received messages msg1, without waiting for thereception of a message msg2.

FIG. 2 shows an example of the power of a near-field radio wavecorresponding to a validation gesture, according to one embodiment ofthe disclosed technology.

The terminal T comprises a means for analyzing the power of the wavereceived by virtue of the electromagnetic-wave conduction capacities ofthe body (IBC) of the user, when the latter makes a validation gestureto the NFC touchpoint. This gesture modifies the characteristics of theradio wave emitted by the touchpoint, and in particular the power ofthis wave.

The variations in power of the radio wave may be divided into 4 distinctperiods. During a period P1 of inactivity, the user has not yet startedhis validation gesture; for example, his hand is still insufficientlynear to the sensing area of the NFC touchpoint. The power of the signalis low; it is for example −70 dBm.

The period P2 of detection of a rising edge starts at a time t(1), whenthe power of the wave suddenly increases. The analyzing means detectsthe time t(1) of the start of the rising edge, for example by computingthe derivative of the power and by monitoring for the point when athreshold sD is reached.

When both the derivative has dropped below the threshold sD, and thepower of the wave has exceeded a power threshold sP, −50 dBm forexample, this means that the rising edge has given way to a plateau. Theplateau period P3 starts at this time, t(T1), which corresponds to thedetection of the start of the validation gesture, i.e. to step T1 of themethod which was described with reference to FIG. 1. The plateau periodP3 lasts for as long as the power of the signal remains above thethreshold sP.

A new period P4 of inactivity starts at a time t(T5), which correspondsto the end of the validation gesture, i.e. to step T5 of the methodwhich was described with reference to FIG. 1, when the power once againdrops below the threshold sP.

The characteristics of the wave that are used, i.e. its power and itsderivative, and the use of the thresholds sP and sD, are merely oneexemplary embodiment among others of the means that may be implementedin order to determine, according to the disclosed technology, the startand end of a validation gesture.

As variants, the end of the plateau is detected when the derivative ofthe power drops below a certain threshold and the power below anotherthreshold. These thresholds may also be determined dynamically withrespect to the power of the plateau (for example, the hand is consideredto have been removed when the power drops by 10 dBm).

The times t(T1) and t(T5), which represent timestamps of the start andend of the validation gesture, may not correspond exactly to the timesTo and Tf, i.e. to the times at which the right is granted and rescindedby the server S, respectively. Specifically, the communication networkused to transmit the messages msg1 and msg2 induces a certain latencytime between the time at which they are sent by the terminal T (stepsT3(1) and T6) and the time at which they are received by the server S(steps S1(1) and S2).

Alternatively, if the times t(T1) and t(T5) are inserted as timestampsinto the messages msg1 and msg2 by the terminal T, the server S may usethem in order to make the start and end of the validation gesturecorrespond exactly to the time at which the right is granted andrescinded.

In the particular embodiments that follow, the attribution of a right isdependent on a plurality of validation gestures being made by one ormore users.

FIG. 3 shows a system for attributing a right depending on theperformance of validation gestures by a plurality of users.

The server Sa attributes a right to all of the users Ua, Ub and Uc,provided that they each make a validation gesture to an NFC touchpoint,i.e. to the touchpoints Ba, Bb and Bc, respectively. The criteria ofattribution of the right in addition include a restriction as regardsthe duration and the moment of each of the validation gestures. Therequested right may for example be an access right to a network, to acomputer application or to a service, or to an action on a softwarerobot, or on a mechanism, such as a request to unlock a secure door.

The server Sa receives messages msg1 and msg2 from the terminals Ta, Tband Tc borne by the users Ua, Ub and Uc, respectively, such as presentedabove with reference to FIG. 1 with a single user. These messages allowthe server Sa to determine, for each user, a time interval IT bounded bythe start and by the end of the validation gesture that he made.

With the intervals IT(Ua), IT(Ub), IT(Uc), the server Sa verifies thatthey meet one or more criteria such as, for example:

-   -   each interval encompasses the same precise moment in time    -   the duration of the intervals is shorter than a maximum value    -   the duration of the intervals is longer than a minimum value    -   the duration of the intervals is located between 2 threshold        values    -   the intervals follow one another in a certain order    -   the intervals follow one another without overlapping    -   the intervals follow one another with overlap of a minimum        duration

The strictness of the criteria will increase as the sensitivity and riskof fraud associated with the right to be attributed increase.

The criteria of attribution of the right may also be partially met, theserver Sa for example merely verifying that a simple majority of theexpected gestures have been made correctly.

In another embodiment, the terminals Ta, Tb and Tc detect only the startof a validation gesture, or the gesture in its entirety. Only the time tof a gesture is therefore determined by the server Sa, and not theinterval of its realization. In this case, the server Sa verifies thatthe times t(Ua), t(Ub), t(Uc) of the validation gestures meet one ormore criteria such as, for example:

-   -   each time is not distant from a precise moment in time by more        than a maximum length of time    -   the times follow one another in a certain order    -   the times follow one another while respecting a minimum        separation duration    -   the times follow one another while respecting a maximum        separation duration

FIG. 4 shows a system for attributing a right depending on theperformance of a plurality of validation gestures by a single user.

In this embodiment, a single user Ud makes, substantiallysimultaneously, a validation gesture with each of his hands, to twoseparate NFC touchpoints, Bd and Be. It is not necessary for the user tobe bearing a terminal on his person, because each touchpoint alsocomprises a device, Td and Te, respectively, for receiving a near-fieldradio wave, in addition to a sending device. The touchpoints Bd and Behave the same capacities as those employed by the touchpoint B to carryout the method described with reference to FIG. 1. Likewise, the devicesTd and Te have the same capacities as those employed by the terminal Tto carry out the method described with reference to FIG. 1. Thetouchpoints are able and configured to communicate with a rights managerSb, by a means possibly other than a near-field radio wave. The rightsmanager Sb possesses at least the same capacities as those employed bythe server S to carry out the method described with reference to FIG. 1.The rights manager Sb may be comprised in a remote server such as theserver Sa described with reference to FIG. 3, but it may also beintegrated into one of the touchpoints Bd or Be, which are thenconnected to each other in any way, for example if the two touchpointsare contained in a single physical installation with two senders and tworeceivers of near-field radio waves.

In this embodiment, the proposed system may thus perform a crosseddetection of the validation gestures. Combined with a physio-dynamicidentification of the user by way of the trails generated via thecharacteristics of the radio waves modified by each of his two gestures,this system is applicable to the field of secure access via biometricauthentication.

In addition, when the start and end times of each of the two gesturesare transmitted to the manager Sb, the same types of time-domaincriteria as those described with reference to FIG. 3 may be used toattribute the right requested by the user.

With reference to FIG. 5, an example of a structure of a device forreceiving a near-field radio wave, according to one aspect of thedisclosed technology, will now be described.

The device 100 implements the method for receiving a near-field radiowave, various embodiments of which were described above.

For example, the device 100 comprises a processing unit 101 that is forexample equipped with a microprocessor μP, and controlled by a computerprogram that is stored in a memory and that implements the methodaccording to the disclosed technology. On initialization, the codeinstructions of the computer program are for example loaded into avolatile RAM 102, before being executed by the processor of theprocessing unit 101.

The device 100 furthermore comprises:

-   -   a nonvolatile ROM 103 intended to contain persistent data;    -   an antenna 104 suitable for sending and receiving, on the radio        channel and over-the-air or via IBC;    -   a demodulator 105 intended to receive, via the antenna 104, a        modulated electrical signal and to convert it into a digital        signal intended to be transmitted to the processing unit 101;        the demodulator 105 is for example used, in step T2(i) of the        receiving method described above;    -   a modulator 106 intended to make a digital signal produced by        the processing unit 101 suitable for transmission by the antenna        104; the modulator 106 is for example used in step T3(i) or step        T6 of the receiving method described above;    -   a switch 107 suitable for connecting to the antenna 104        alternatively the demodulator 105 (receive mode) and the        modulator 106 (send mode);    -   a detection circuit 108 intended to detect the start and end of        a validation gesture via analysis of the radio wave, whether it        is modulated or not, and especially of its power and of the        derivative of its power; this circuit comprises means for        detecting the radio-wave modifications that result from a        validation gesture, from a start of said gesture, and from an        end of said gesture; the validation circuit 108 is for example        used in step T1 or step T5 of the receiving method described        above; the power and the derivative may be computed from the        analogue signal or completely digitally;    -   an optional clock 109 intended to interact with the processing        unit 101, in order, inter alia, to include a timestamp in the        messages msg1 or msg2.

The device 100 is stand-alone and portable; it is equipped with abattery or cell stacks of small size in order to be transported by auser. Such a device 100 may for example be implemented in a mobileterminal, or be a mobile terminal suitable for implementing a receivingmethod according to the disclosed technology.

With reference to FIG. 6, an example of a structure of a device formanaging a right that is attributed on the basis of a plurality ofvalidation gestures made by at least one user, according to one aspectof the disclosed technology, will now be described.

The device 200 implements the method for managing rights attributed onthe basis of a plurality of validation gestures made by at least oneuser, various embodiments of which were described above.

For example, the device 200 comprises a processing unit 201 that is forexample equipped with a microprocessor μP, and controlled by a computerprogram that is stored in a memory and that implements the methodaccording to the disclosed technology. On initialization, the codeinstructions of the computer program are for example loaded into avolatile RAM 202, before being executed by the processor of theprocessing unit 201, with a view to attributing a right to at least oneuser on the basis of the times at which a plurality of validationgestures are detected.

The device 200 furthermore comprises:

-   -   a nonvolatile ROM 203 intended to contain persistent data;    -   a receiver 204 configured to obtain a plurality of data relating        to detection times of modifications of a characteristic of a        near-field radio wave, said data being referred to as detection        data.

The device 200 may be comprised in a server such as the server S, Sa orSb, or be comprised in an NFC touchpoint such as for example thetouchpoint B, or one of the touchpoints Ba, Bb, Bc, Bd, or Be.

While certain embodiments have been described, these embodiments havebeen presented by way of example only and are not intended to limit thescope of the disclosure. Indeed, the novel methods and systems describedherein may be embodied in a variety of other forms. Furthermore, variousomissions, substitutions and changes in the systems and methodsdescribed herein may be made without departing from the spirit of thedisclosure. The accompanying claims and their equivalents are intendedto cover such forms or modifications as would fall within the scope ofthe disclosure.

Features, materials, characteristics, or groups described in conjunctionwith a particular aspect, embodiment, or example are to be understood tobe applicable to any other aspect, embodiment or example described inthis section or elsewhere in this specification unless incompatibletherewith. All of the features disclosed in this specification(including any accompanying claims, abstract and drawings), and/or allof the steps of any method or process so disclosed, may be combined inany combination, except combinations where at least some of suchfeatures and/or steps are mutually exclusive. The protection is notrestricted to the details of any foregoing embodiments. The protectionextends to any novel one, or any novel combination, of the featuresdisclosed in this specification (including any accompanying claims,abstract and drawings), or to any novel one, or any novel combination,of the steps of any method or process so disclosed.

Furthermore, certain features that are described in this disclosure inthe context of separate implementations can also be implemented incombination in a single implementation. Conversely, various featuresthat are described in the context of a single implementation can also beimplemented in multiple implementations separately or in any suitablesubcombination. Moreover, although features may be described above asacting in certain combinations, one or more features from a claimedcombination can, in some cases, be excised from the combination, and thecombination may be claimed as a subcombination or variation of asubcombination.

For purposes of this disclosure, certain aspects, advantages, and novelfeatures are described herein. Not necessarily all such advantages maybe achieved in accordance with any particular embodiment. Thus, forexample, those skilled in the art will recognize that the disclosure maybe embodied or carried out in a manner that achieves one advantage or agroup of advantages as taught herein without necessarily achieving otheradvantages as may be taught or suggested herein.

Certain terminology may be used in the following description for thepurpose of reference only, and thus is not intended to be limiting. Forexample, terms such as “upper”, “lower”, “upward”, “downward”, “above”,“below”, “top”, “bottom”, “left”, and similar terms refer to directionsin the drawings to which reference is made. Such terminology may includethe words specifically mentioned above, derivatives thereof, and wordsof similar import. Similarly, the terms “first”, “second”, and othersuch numerical terms referring to structures neither imply a sequence ororder unless clearly indicated by the context.

Conditional language, such as “can,” “could,” “might,” or “may,” unlessspecifically stated otherwise, or otherwise understood within thecontext as used, is generally intended to convey that certainembodiments include, while other embodiments do not include, certainfeatures, elements, and/or steps. Thus, such conditional language is notgenerally intended to imply that features, elements, and/or steps are inany way required for one or more embodiments or that one or moreembodiments necessarily include logic for deciding, with or without userinput or prompting, whether these features, elements, and/or steps areincluded or are to be performed in any particular embodiment.

Conjunctive language such as the phrase “at least one of X, Y, and Z,”unless specifically stated otherwise, is otherwise understood with thecontext as used in general to convey that an item, term, etc. may beeither X, Y, or Z. Thus, such conjunctive language is not generallyintended to imply that certain embodiments require the presence of atleast one of X, at least one of Y, and at least one of Z.

The terms “comprising,” “including,” “having,” and the like aresynonymous and are used inclusively, in an open-ended fashion, and donot exclude additional elements, features, acts, operations, and soforth. Likewise, the terms “some,” “certain,” and the like aresynonymous and are used in an open-ended fashion. Also, the term “or” isused in its inclusive sense (and not in its exclusive sense) so thatwhen used, for example, to connect a list of elements, the term “or”means one, some, or all of the elements in the list.

Overall, the language of the claims is to be interpreted broadly basedon the language employed in the claims. The language of the claims isnot to be limited to the non-exclusive embodiments and examples that areillustrated and described in this disclosure, or that are discussedduring the prosecution of the application.

Although the disclosed technology has been described in the context ofcertain embodiments and examples, it will be understood by those skilledin the art that this disclosure extends beyond the specificallydisclosed embodiments to other alternative embodiments and/or uses ofthe embodiments and certain modifications and equivalents thereof. Thescope of the present disclosure is not intended to be limited by thespecific disclosures of preferred embodiments in this section orelsewhere in this specification, and may be defined by claims aspresented in this section or elsewhere in this specification or aspresented in the future.

What is claimed is:
 1. A method for receiving a near-field radio wave,the wave being received using electromagnetic-wave conduction capacitiesof the body of a user able to make a validation gesture that modifiescharacteristics of the radio wave, the method comprising detecting afirst modification of a characteristic of the radio wave, the firstmodification being resultant from a start of the validation gesture; anddetecting a second modification of a characteristic of the radio wave,the second modification being resultant from an end of the gesture, theacquisition of a right for the user being dependent on the firstmodification and the second modification.
 2. The method of claim 1,wherein the radio wave comprises frames, the method comprisingextracting, from a frame of the radio wave, an identifier of a devicewhich sent the near-field radio wave.
 3. The method of claim 1, whereinthe radio wave comprises frames, the method comprising extracting, fromat least one frame of the radio wave, a random factor time-variableverification code.
 4. The method of claim 1, comprising sending, to aserver that manages the right, a detection message relating to at leastone detection.
 5. The method of claim 4, wherein the detection messagecomprises at least one of: an identifier of the device which sent thenear-field radio wave; and a random factor; and a datum relating to theuser.
 6. The method of claim 4, further comprising sending a pluralityof successive detection messages up to the detection of the secondmodification, a first message of the plurality of successive detectionmessages being sent as soon as the first modification is detected. 7.The method of claim 2, wherein, before a datum is extracted from aframe, sending a return message indicative of the detection of thevalidation gesture to the device which sent the near-field radio wave.8. A device configured to receive a near-field radio wave usingelectromagnetic-wave conduction capacities of the body of a user, theuser able to make a validation gesture that modifies characteristics ofthe radio wave, the device comprising a detection circuit, a processor,and a memory coupled to the processor, the memory containinginstructions that are intended to be executed by the processor in orderto: detect a first modification of a characteristic of the radio wave,the first modification being resultant from a start of the gesture; anddetect a second modification of a characteristic of the radio wave, thesecond modification being resultant from an end of the gesture, theacquisition of a right for the user being dependent on the detections ofthe first and second modifications.
 9. A system for acquiring atemporary right, the system comprising: the receiving device of claim 8;a sending device configured to emit a near-field radio wave; and arights-managing device configured to attribute a right dependent upon atleast one datum relating to the start of the validation gesture and tothe end of the validation gesture.
 10. The system of claim 9, wherein:the sending device comprises a means for detecting a physical contactwith the user; and the rights-managing device is configured to attributethe right dependent upon a datum relating to physical contact.
 11. Thesystem of claim 9, wherein: the sending device further comprises a meansfor inserting, inter the near-field radio wave, a random factor knownthe to the rights-managing device; and the receiving device furthercomprises: a means for extracting the random factor, and a means fortransmitting the random factor to the rights-managing device.
 12. Thesystem of claim 9, wherein the sending device comprises: a means fordetecting a physical contact with the user; and a means for inserting,inter the near-field radio wave, a random factor known the to therights-managing device, the inserting means being activated afterdetection of the physical contact with the user.
 13. A computercomprising a processor and a memory, the memory having stored thereoninstructions which, when executed by the processor, cause the computerto implement the method of claim
 1. 14. A non-transitory,computer-readable storage medium having stored thereon instructionswhich, when executed by a processor, cause the processor to implementthe method of claim 1.